Means for preventing the formation of ice on airplanes and the like



Jan. 9, 1934. E. DRISCOLL 1,943,062

MEANS FOR PREVENTING THE FORMATION OF ICE ON AIRPLANES AND THE LIKE Filed July 29. 19:51

INVENTOR IwkAITOR Patented Jan. 9, 1934 UNITED STATE PATENT OFFICE- MEANS FOR PREVENTING THE OF ICE 0N AIBPLANES AND FORMATION THE LIKE This invention relates to means for preventing the formation of ice on airplanes and the like, and an object of the invention is to provide a simple, practical and efiicient means to this end.

A further detailed object is to provide a covering which is of a fiexible character adapting it to be readily bent or twisted or otherwise formed to mate the underlying contour of the surfaces to which it is attached.

A further detailed object is to provide a device which will be electrically heated and which will be economical in the consumption of electric current.

A further object is to so construct the device that it will become heated only in the locality or localities where moisture, and .the attendant danger of ice formation, is present from time to time.

A more detailed object is to provide means in the form of separate heating units adapted for attachment as a cover onto the portion or portions of the airplane or the like which it is desired to protect against the formation of ice.

A further detailed object is to so construct the units that they may be fitted side by side over the surfaces to be protected and so that they may be connected together electrically-in a convenient manner, each unit being preferably adapted for independent attachment and removal at all times.

Other objects and aims of the invention, more or less specific than those referred to above, will be in part obvious and in part pointed out-in the course of the following description of the elements, combinations, arrangements of parts and applications of principles constituting the invention; and the scope of protection contemplated will be indicated in the appended claims.

In the accompanying drawing which is to be taken as a part of this specification, and in which I have shown merely a preferred form of embodiment of the invention:-

Fig. 1 is a perspective view to illustrate the manner in which this invention may be applied to the wings of an airplane.

Pig. in a detail perspective view of one of the units proposed bythis invention and showing the manner of connection with an adjacent unit.

Pie. 3 is an enlarged fragmentary sectional view taken upon the plane of line m rn of Fig. 2, and

illustrating the presence of a suitable filler intermediate the heating wires employed, and

. Fig. 4 is a similar sectional view butillustrating a modified form of filler.

Referring to the drawing fordescribing in de- It will be understood of course that the terminals erence character L indicates the body of an airplane having wings (3-6.

The protecting covering contemplated by this invention is shown for illustration as being applied to the wings G and as consisting of a series 59 v of separate units HH. The units are all substantially alike except that of course they may be made of various sizes and shapes. 'I'heyare as flexible as possible so that they can be nicely fitted to the contour of the surface which they 6 protect. I

Any means may be employed for fastening them in position, either screws, bolts, rivets or cement and they may be placed over the entire wing or other element or just over a given se- 10 lected portion, as the situation may demand.

Each unit is shown to consist of a frame 1 through which extends two bus rods or wires as 2 and 3. Terminals 4 and 5 are connected with opposite ends of bus 2, and terminals 6 and 7 are connected with opposite ends of the bus 3. These terminals 4 and 5 and 6 and 7 are shown'as means by which jumpers or their equivalent as 8 may be employed for connecting together the buses of one unit with those of the next adjacent 30 unit in a general manner as indicated in Fig. 2.

4-7, and the Jumpers 8 may if desired be arranged so as to stand wholly beneath the uppersurface of the units so that said upper surface, as pictured in Fig. 1, will not disclose the presence of said terminals and jumpers but will be smooth and unobstructed.

A series of wires as 99 extend from the bus 2 across the frame toward the bus 3 but do not engage the bus 3. Another set of wires as 10-10 extends in the opposite direction across the frame from the bus 3 to the bus 2 but is short of the bus 2. The wires of the two sets 9-9 and 10-10 lie side by side allsubstantlally in the same horizontal plane and between the top and bottom planes of the frame 1, as clearly indicated in Figs. 3' and 4.v They are spaced away from each other a slight distance and a suitable insulating medium as 11 is provided for insulating the wires from each other and for holding them in position. a

It is intended however that the insulating material 11 shall be of a character such that when dry it is an insulator yet when wet it becomes capable of conducting current. It is intended that under normal dry conditions no current will pass through the insulating material between any of the and that hence no electric current will be consumed, but thatas' soon as any will provide a resisting conductive path between the wires present in that particular portion so that that particular portion of the insulating material will become heated thereby melting anyice formation and of course maintaining the presence of moisture so that the heat will continue in that particular portion of the cover as long as there is a tendency of ice formation.

It will be seen therefore that only the portion of the cover which becomes moist or wet will consume electric current, allother portions being dry and therefore passing no current.

' It will also be seen that the device is automatic claim as new and desire to secure by Letters Patin the performance of its function. No switches are required to direct current to selected localities and no switch is necessary to put the device into and out of operating condition.

A supply of current may be connected with the buses 1 and 2 in any appropriate manner as through lead wires 12 and 13, and this connection may be continuous, yet no current will flow except as the automatic result of the wetting of -some part or parts of the protecting cover.

Current to the lead wires may be obtained from any suitable source, either from a generator driven by the airplane motor, or from a generator driven by a wind operated propeller, or otherwise. If desired theleadwires 12 and 13 may simply be shuntedin onthemainlinewires Hand 15 of the lighting or heating system of the airplane as indicated, there being in this instance preferably employed a pair of resistance elements as 16 and 17 provided in the lines 12 and 13 to guard against the possibility of any injury befalling the lighting or heating system in the possible event of a short circuit between the wires 12 and 13. Of course if desired a cut-out switch as 18 may be provided in the line 12-13, but as above mentioned this is not essential.

While any appropriate material may be employed from which to form the various parts of the covering material herein proposed it is suggested that the frame 1 may be formed of rubber or a suitable rubber-like composition. It is of course constructed to provide permanent insulation between the buses 1 and 2. And it-may be formed with any number of apertures as 19-19 or other means to facilitate the fastening of the units onto the surface which is to be protected. It is suggested that the insulating material 11 may if desired consist of asbestos woven or otherwise suitably formed to constitute an absorbent fire proof insulating body.

In Fig. 3 it is suggested that the insulation may take the form of separate fillers as 20-20 extending transversely across the frame one'flller interposed between each pair of wires 9-10, the fillers having opposite longitudinal edge grooves 21 fitting to and receiving wires 9-10 so as to,

hold them in proper position, it being understood that the fillers themselves are wedged into the "frame or are otherwise held against displacement from the frame.

In Fig. 4 it is suggested that the insulating material 11 may if desired be in the form of opposite sheets as 22-22. one-lying on top of the wires 9-10 and the other underlying said wires, the

. twosheets having grooves as 23 and 24 in their abutting faces adapted to receive and retain the wires definitely spaced from each other. The

sheets22wiil ofcoursebeheldintheframeby friction or other suitable means.

It will be seen that the device as thus described is simple and inexpensive to manufacture and that when made up in units as proposed it may be applied onto any part or parts of the surface which is to be protected and that in so applying said units they may be bent, curved and otherwise fitted nicely to said surface.

As many changes could be made in this construction without departing from the scope of the invention as defined in the following claims, it is intended that all matter contained in the above description, or shown in the accompanying drawing, shall be interpreted as illustrative only and not in a limiting sense.

Having thus described my invention, what I eat is:

1. A device for preventing the formation of ice upon surfaces, said device consisting of a cover for said surface absorbent throughout so as to absorb moisture wherever moisture falls thereunto, and electrically operable heating means including opposite polarity conductors spaced apart by portions of the absorbent material of the cover adapted to pass current through moisture in said material and to thereby generate heat at any locality where moisture has fallen onto and wet said material, said conductors being inoperative to produce heat where the material of the cover is dry.

2. A device for preventing the formation of ice upon surfaces, said device consisting of a cover for said surface, said cover being flexible so that it may be bent to conform to irregularities and curvatures of the surface to be protected, means by which said cover may be attached onto said surface, said cover including a plurality of conductor wires arranged side by side adjacent conductors being of opposite polarity, and means separating said conductors of a character so that when moist it will pass current between said conductors and thereby heat the moisture but when dry it will insulate said conductors, said conductors and said separating means being of a flexible character so as to be bendable as part of the cover to conform therewith to the surface to be protected.

. 8. A device for preventing the formation of ice upon surfaces, said device consisting of a cover for said surface, means by which said cover may be attached onto said surface, said cover including a plurality of conductor wires arranged side by side adjacent conductors being of opposite polarity, and means separating said conductors of a character so that when moist it will pass current between said conductors and thereby heat the moisture but when dry it will insulate said conductors.

4. A device for preventing the formation of ice upon surfaces, said device consisting of a cover for said surface, said cover being made up of a plurality of separately formed and independently attachable units, each of said units consisting of a plurality of conductorsarranged spaced apart,

and for said filler means.

5. A heating unit intended for use in the protection of surfaces against the formation of ice upon said surfaces, said heating unit consisting of a ocation plurality of conductors arranged spaced apart, adjacent conductors being of opposite polarity, filler means interposed between said conductors of a character so that when moist it will pass current between said conductors and thereby heat the moisture but when dry it will insulate said conductors, and carrier means tor said conductors V and for said filler means, together with means by which to electrically connect said unit with adjacent other like units to supply current of opposite polarity to the adjacent conductors throughout the units.

6. In a flying machine having an electrical supply system and having a surface requiring to be protected against the formation of ice thereon, a cover for said surface including a plurality of conductors arranged spaced apart, adjacent conductors being connected with" opposite sides of the electrical supply system and being therefor of opposite polarity and means spacing said conductors of a character so that when moist it will pass current between said conductors and thereby heat themoisturebutwhendryitwillinsulatesaid conductors.

I. A heating unit intended for use in the protection of surfaces against the formation of ice electric circuit, a set or conductors spaced apart along the length 01' one of said buses extending therefrom toward the second bus but terminating short or said second bus, a second set of conductors spaced apart along the length or the second bus and extending therefrom toward the first bus but terminating short of the first bus, the conductors of said two sets alternating with each other so that adjacent conductors throughout are of opposite polarity, and means spacing said conductors of a character so that when moist it will pass current between said conductors and thereby heat the moisture but when dry it will insulate said conductors.

EDWARD A. DRISCOLL. v 

